Hello All,

I will try to frame my question in short.

End Goal : REST API Integration from Salesforce to a InHouse Lead Management System(LMS2)

SUCCESS Through Chrome APP
1.  All i need to do is retrieve values from LMS2. When i tried to use the Chrome APP 'Advanced Rest Client' and have passed the appropriate URL and Content in XML/TEST format in the form of POST methoed I was able to retrieve the values from LMS2 database.
For EG : If i pass 92126 then i was able to get 'SAN DIEGO' which is correct. 

Here is the link (https://chrome.google.com/webstore/detail/advanced-rest-client/hgmloofddffdnphfgcellkdfbfbjeloo?hl=en-US)for Advanced REST Client.


PROBLEM from Salesforce :

2) When i created this REST class in SAlesforce and tried invoking the End Point then its throwing this error. 

System.HttpResponse[Status=Service Unavailable, StatusCode=503]

public with sharing class LmsRestApiIntegration {

//LmsRestApiIntegration.invokeRestAPI()
@future(callout = true)
public static void invokeRestAPI(){
String URL = 'http://pasquote-bfapp.tent.trt.csaa.pri/QuickQuoteWebSvc/QQWebSvc.asmx';
String xmlContent = '';
xmlContent = '<?xml version="1.0" encoding="utf-8"?>';
xmlContent = xmlContent + '<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">';
xmlContent = xmlContent + '<soap:Body>';
xmlContent = xmlContent + '<GetCityListFromZip xmlns="http://www.csaa.com/irv/quickquote/auto/2006/10/01">';
xmlContent = xmlContent + '<zipcode>92126</zipcode></GetCityListFromZip>';
xmlContent = xmlContent + '</GetCityListFromZip>';
xmlContent = xmlContent + ' </soap:Body>';
xmlContent = xmlContent + '</soap:Envelope>';
Http h = new Http();
HttpRequest req = new HttpRequest();
req.setBody(xmlContent);
req.setHeader('content-type','text/xml');
req.setHeader('content-length', '0');
req.setEndpoint(URL);
req.setHeader('SoapAction', 'http://www.csaa.com//irv/quickquote/auto/2006/10/01/GetCityListFromZip');
req.setMethod('POST');
String response = '' ;
HttpResponse res = h.send(req);
response = res.getBody();

System.debug('Response :'+response);

}
}

Please guide.

Thank You
Shri